In-vivo imaging devices such as, for example, ingestible imaging capsules, for imaging of the gastrointestinal (GI) tract or other body lumens of a patient may wirelessly transmit image data to an external data recorder. The data recorder may be affixed to the patient by a strap or a belt so that the patient may freely perform normal actions during an observation period that may begin after swallowing the in-vivo imaging device and end upon its excretion. The data recorder may have radio communication capability and it may have connected to it one or more antennas for receiving the image data transmitted by the in-vivo imaging device and the data recorder may have a memory for storing the received image data. After the observation period, the patient may deliver the data recorder to an operator, for example, a health professional who may download the stored image data for processing and for performing analysis of the GI tract for diagnosis purposes.
The image data includes images of the GI tract captured by an imager in the in-vivo imaging device as it passes through the GI tract. The image data may be downloaded from the data recorder to a workstation, or the like, where it may undergo various forms of image processing prior to analysis of the images of the GI tract for diagnosis purposes. The images may be obtained using illumination sources of light radiation, for example, light emitting diodes (LEDs), which may be located in the in-vivo imaging devices. Emitted light radiation may illuminate target areas of the GI tract, or other body lumens, and light radiation may be reflected back from the target areas to the imager in the in-vivo imaging device thereby producing images of the target areas. The imager may be any array of light sensitive elements, for example a charge coupled device (CCD), and the illumination sources may be broad spectrum white light sources. Colored images may be obtained by using an imager with colored filters covering its light sensitive elements. For example, red, green and blue filters may be used. The color filters may be designed to be relatively broadband in order to reduce intensity loss of light passing through them. It is sometimes required to perform narrow band imaging. For example, using a red light illumination source. In such cases, an imager sensitive to the red light illumination is used. Such an imager cannot be used for two different types of narrow band illumination sources, for example for both a red and a blue light illumination source.